In a formula compound I, R1 'is morphine, replaced by C1-C6 tar, and replaced by C1-C6 tar, pyridinol, picolinate, etc.; r2'esh is C1-C6 tar, replaced by alcox C1-C6; R3 is h, halogenated atom or C1-C6 tar. The preferred compounds are: 3 - (1-methyletoxi) - 6, 7, 8, 9-tetrahydropyridine [2, 3-F] [1, 4] oxazepina; N-methyl-N - (1-methyl) - 6, 7, 8, 9-tetrahydropyridine [2, 3-F] [1, 4] oxazepina; 3-cycloacrylonitrile-6, 7, 8, 9-tetrahydropyridine [2, 3-F] [1, 4] oxazepina. These compounds have 5-h2c util receptor activity in the treatment of low urinary tract symptoms, obesity and / or organ obesity.REFERIDA A UN COMPUESTO DE FORMULA I, DONDE R1' ES MORFOLINILO SUSTITUIDO CON ALQUILO C1-C6, PIPERIDILO SUSTITUIDO CON ALQUILO C1-C6, PIRROLILO, IMIDAZOLILO, ENTRE OTROS; R2' ESH, ALQUILO C1-C6 OPCIONALMENTE SUSTITUIDO CON GRUPOS ALCOXI C1-C6; R3 ES H, UN ATOMO DE HALOGENO O ALQUILO C1-C6. SON COMPUESTOS PREFERIDOS: 3-(1-METILETOXI)-6,7,8,9-TETRAHIDROPIRAZINO[2,3-f][1,4]OXAZEPINA; N-METIL-N-(1-METIL)-6,7,8,9-TETRAHIDROPIRAZINO[2,3-f][1,4]OXAZEPINA; 3-CICLOPROPIL-6,7,8,9-TETRAHIDROPIRAZINO[2,3-f][1,4]OXAZEPINA; ENTRE OTROS. DICHOS COMPUESTOS SON ACTIVADORES DEL RECEPTOR DE SEROTONINA 5-HT2C UTIL EN EL TRATAMIENTO DE UN SINTOMA URINARIO INFERIOR, OBESIDAD Y/O PROLAPSO DE ORGANOS